The appointment of Rod Phillips reunites him with Postmedia president and CEO Paul Godfrey, who had been chairman at OLG until he was dismissed last May.
Phillips resigned as president and chief executive at OLG on Jan. 22.
His previous experience included serving as president and chief executive of Shepell.fgi, a workplace health and productivity solutions company, and serving as chief of staff to former Toronto mayor Mel Lastman.
Postmedia, the owner of the National Post and several other big-city newspapers, also announced Martin Nisenholtz will join its board as a director.
Nisenholtz, a venture partner at FirstMark Capital in New York, will also serve as chairman of the board's digital oversight committee.
"These appointees bring impressive experience in business transformation and modernization and are both experts on matters of industry evolution," said Godfrey in a statement.
On Tuesday, Postmedia laid off three reporters and two staff from its parliamentary bureau and moved its politics editor, along with the remaining four political reporters, to the Ottawa Citizen.
The cuts were the latest in a round of downsizing in the journalism industry, which has been squeezed in recent years due to declining ad revenue and more people consuming digital news rather than traditional print media.